PEB20321 Datasheet, PDF (364/366 Pages) Siemens Semiconductor Group – Multichannel Network Interface Controller for HDLC MUNICH32X

PEB 20321
PEF 20321
MUNICH32X Bus Utilization
6
Bus Load T1 - Real System
ITD10851
%
5
4
PCI Bus Load
3
Transfer of Overhead
2
1
Transfer of Data
0 _{4 12 20 28 36 44 52 60 68 76 84 92 100 108 Bytes 128}
Packet Size
Figure 113 Typical System, T1
The control overhead per packet is constant which results in an increased bus load if the
serial line data rate is achieved by very small packets. The overhead can be neglected
for packet sizes greater than 32 bytes.
On the serial line the 16 bit CRC and one shared flag per packet also appears as a
constant overhead which reduces the effective data rate for small packets.
The influence of bit-stuffing in HDLC protocol mode also reducing the effective data rate
is neglected.
Data Sheet
364
2001-02-14